EE WAS ROOF BOLTING ON THE RIGHT SIDE OF THE BOLTER WITH CO-WORKER. THE CUT WAS A FIRST TURN TO THE RIGHT BETWEEN ENTRY #3 AND #4. EE WAS PREPARING TO INSTALL THE FIRST BOLT IN THIS FIRST CUT. HE WAS SWINGING THE BOLTER BOOM TOWARD HIM WHEN THE DRILL POT HIT HIS LEFT KNEE PUSHING HIS LEG TOWARD THE RIB. THIS RESULTED IN A CONTUSION TO THE LEFT KNEE CAP. EE WORKED UNTIL 2-23-04, OFF